Syringe



Allg- 201963 c. H. HAMILTON 3,101,084

sYRNGE Filed May s, 1962 `gaie.

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f BWM United States Patent 3,101,084 SYRINGE Clark H. Hamilton, 737Whitley, Whittier, Calif. Filed May 8, 1962, Ser. No. 193,093 '7 Claims.(Cl. 12S- 213) This invention relates generally to syringes andrelatesmore particularly to syringes having a very small volumetric lcapacity.

While the invention has particular utility embodied in syringes ofextremely .small volumetric capacity, and is shown and describedembodied therein, it is to be understood that its utility is notconlined thereto.

Various Aproblems and diiiiculties have been encountered in providingsyringes of extremely small volumetric capacity land it is an object ofthe present invention to provide such a small capacity syringewhichvwill solve said problems and overcome said difficulties.

Itis another object of the invention to provide -a syringe of thischaracter which has a zero loss of medicant or chemical sample.

It is still another object of the invention to provide a device of thischaracter which will effectively handle extremely small `amounts offluid (gas or liquid), such as medicants, chemicals, or the like. t

It is a further object of the invention to provide a device of thischaracter wherein lthe needle lacts with both -as a syringe fluidreservoir and an injection element.

it is a still further object oi the invention to provide a device ofthis chanacter wherein a hard needle tubing is precisely titted with aplunger or plunger surface of a hard :metal dissimilar fromthe needle orinterior surface rot the needle contacted by the plunger surface.

It is another object of the invention to provide a device of thischaracter wherein the plunger displacement is read directly on agraduated scale.

It is still lanother object of the invention to provide va.

`device of this character whereinthere is a plunger guide assembly whichsupports the very small Adiameter plunger and 4permits free precisemovements thereof.

lt is a further object of the invention to provide a seal effective forleakage of tluid, gas or liquid resulting from wear or corrosion.

lt is la still further object of the invention to provide a device ofthis character which prevents wiping in of dirt by the plunger from theoutside, `such as would make the syringe inoperable. v Y

It is another object of the invention to provide a device of thischaracter wherein capillary movement of liquid up the plunger and needlesurfaces, such as woulddestroy `the precision of 'delivery volume, isprevented.

A further object of the invention is to provide ya device of thischaracter wherein air seepage is prevented.

lt is a still further object of the invention toprovide a device of thischaracter that is extremely accurate.

It is another object of the invention to provide a device of thischaracter that is extremely reliable.

It is still another object of the invention to provide a device of thischaracter that is relatively simple in construction.

A further object of the invention is to provide a device of thischaracter that `may be readily and easily assembled, or disassembled,for servicing or replacement of parts.

It is a still further object of the invent-ion to provide ice a deviceof this character that is relatively inexpensive to manufacture.

The characteristics land advantages of the invention are -furthersufliciently referred to in `connection with the following detailed'description of the accompanying drawings, which represent oneembodiment. After considering this example skilled persons willunderstand that many variations may be made without departing from theprinciples disclosed and I contemplate the employeinent of anystructures, arrangements or modes of operation that are properly Withinthe scope of the appended claim-s.

Referring' to the drawings, which lare for illustrative purposes` only:

FIG. l is a longitudinal section through a syringe ernbodying thepresent invention;

FIG. 2 is a side view of the device;

FlG. 3 is an enlarged .longitudinal sectional View of a portion of saidsyringe;

f FIG. 4 is an enlarged side view, partially in section, or the outerend of the plunger assembly; i

FIG. 5 is a sectional view taken on line 5-5 of FIG.

,.fFIG. 6 is an enlarged longitudinal sectional view of an alternativearrangement.

Referring more particularly to the drawings, there is shown a syringehaving a needle assembly, indicated generally lat 1t), including ahollow or tubular needle 12 provided -with a sharp point 14 at the outeror tree end thereof, said needle serving both las `a syringe reservoirand as` an injection device. Needle l2 may be of any suitable material,such as a hard metal, platinum alloy or stainless steelbeing examples ofsuitable materials for such needles. t

fAt the end of the needle opposite the point 14 said needle is providedwith a female needle hub 16 having a wall 18 at its outer end providedwith an axial opening therein for reception of the adjacent end portionof the needle 12, said needle being welded or staked, as indicated Yat20, to said hub. Hub 16 has a recess extending inwardly from theopopsite end which is open. Extending from the open end, a portion ofsaid hub is internally threaded las at 22, there being a gasket chamber24 at the inner end `ol? the recess inthe hub 16.

The needle assembly -10 is connected to a volume indicating Ydevice orassembly, indicated `gener-ally at 26, saidassembly comprising atransparent body 28 of 'any suitable material, such as glass, forexample. At the outer end the body 28 is provided with lan outwardlyextending annular lian-ge 30 and there is `an faxia'l bore 32 throughsaid body, said 'bore flaring outwardly tat the flanged end of the body,said flare portion of the bore being indicated at 34. t

Onthe exterior of the body there is a scale, indicated i `generally at36, which is put on said body by any suitable-well known means, such assilver screening.

At the endof the body 28 opposite the iiange 30 thereof a zero stop andneedle screw sleeve 40 is disposed `in the outer end portion of the bore32., said zero stop and needle screw sleeve being cemented in said boreby any suitable well known cement, such as epoxy cement, for example. Aportion of the outer end of sleeve it? extends outwardly beyond theadjacent end of the body 2S and has disposed thereon a Imale needlescrew 42 having a reduced diameter externally threaded outer end portion44 on which the yfemale threaded needle hub 16 is screwed. The maleneedle screw 42 is secured to the zero stop sleeve 4i) by any suitablemeans, such as, for example, welding, cementing or staking. It is to benoted that the inner end 46 of the zero stop sleeve 4t? is in exactregister with the adjacentend of the scale 36 which is the zero point ormark of said scale. h

The interior diameter of the zero stop sleeve 40 1s sufliciently largeto receive therein a forward end portion of a tubular inner plungerguide 50, said forward end portion of the guide Sill being secured inthe Zero stop sleeve by any suitable means, such as cementing, or thelike. Inner plunger guide is arranged axially in the bore 32 in body 2Sand extends rearwardly from the stop sleeve 4l). As shown in FIG. l.-the inner plunger guide extends outwardly or rearwardly of the angedend of the body 28 although it need not extend this far rearwardly. Itis to be noted that the forward end of the Zero stop sleeve and theforward end'of the inner plunger guide terminate in the same plane asthe forward end of the reduced diameterexternally threaded part 44 ofthe male needle screw 42.

It is also to be noted that the zero stop'sleeve is relatively short andextends but a short distance into the forward end portion of the body28, thus leaving a major portion of the bore 32 outwardly of `the outerend 46 of the'zero stop sleeve free ifor slid'able reception of atubular volume indicating plunger Kguide 52, said Volume indieatingplunger guide 52 being slidable on the inner plunger guide 50.

At its outer ends the volume indicating plunger guide has a button andplunger retaining groove 56 which is shown as bein-g integral with saidvolume indicating plunger guide 52 although saidbutton and plungerretaining screw may be a separate part secured to the plunger guide 52by cementing, welding or other suitable means.

* The button and plunger retaining screw is provided with an axial boreof the same size as the bore or passage through the plunger guide 52 andforms a continuation thereof. A freeend portion of the button andplunger retaining screw is externally threaded for threadable receptionof a thumb button 58 which has an axial tapped t bore `6i) inthe forwardend thereof,the'rear end of said button being convex and said bore isclosed at the convex orback side.

Inner plunger guide 50 has an internal bore or passage extending axiallytherethrough of substantially the same size as the internal diameter ofthe needle 12 and a plunger 6141is slidablyv disposed within the innerplunger guide and the bore or passage through the needle 12.

It is to be noted that the plunger is of a dissimilar material or metalfrom that of the needle and said plunger may be, for example, oftungsten or a chrome plated wire. Plunger 64 is precisely Y tted -withinthe boreor passage of the needle but is slidable therein.

TheV back or rear end of the plunger is secured to a plunger retainingbutton-66 by welding or other suitable means, said button being disposedin a recess 68 at the innerend of the tapped bore 60 of the thumb buttonand when said thumb button is screwed onto the button and plungerretaining screw of `the volume indicatinggplunger guide, the plunger andplungerguide 52 are secured together by the thumb button for operationtogether.

The plunger extends through the chamber 24 of the hub `16 and there isgasket material 70 in said chamber. The gasket material is of suchcharacter that it will flow under pressure which is created by thescrewing of the hub 16 onto the part 44 of the needle screw 42. Onesuitable gasket material comprises fluorocarbon resins, such as Teflon(which is the registered trademark of E. I. du Pont de Nemours, Inc.)for such resins. The flowing under compression'of the gasket materialprovides a gas and liquid-tight seal for the plunger portion (i. passingthrough the seal 70- while permitting operative movements of saidplunger.

The needle 12 not only functons as a needle but also functions as avolumetric syringe barrel reservoir, the volume of fluid in said needlebeing precisely displaced by l scoped position the inner or forward endof the volume indicating plunger guide engages the rear end of the zerostop sleeve at which time the forward end of the plunger bottoms at theneedle point. Consequently there is no loss of fluid, gas or liquidhandled by the syringe. In other words, there is a zero loss of suchfluids.

The volume indicating plunger guide 52 and the inner plunger guide 50support the plunger in alignment and allow yfree plunger movement withhigh precision. Further, by the precise fitting and telescoping plungerguides, or guide sleeves 5G and 52, respectively, the plungerdisplacement may be read on the graduated outboard scale 36. Thisplunger displacement is indicated by the 4forward end 74 of the volumeindicating plunger guide as it registers with the various markings orlines of said scale 36.

The sealing gasket may be initially in the shapeA of a tubular partslidably receivable in the chamber 24 and slidably receiving theplunger. The gasket element must be" somewhat longer than the chamber 24and when the hub 16 is screwed onto the part 44 of the needle screw l42,the material of said gasket is crushed or compressed in said chamber tosealingly engage the interior of the needle hub 16 and the portion ofthe plunger disposed therein at any particular time. f

The cmshedlsealing gasket acts in several ways. It seals for grossleakage of liquid or gas resulting fro-m wear or corrosion. It preventswiping in of dirt by the plunger from` the outside which would make thesyringe inoperative. Also, 4it prevents capillary movement of liquids upthe plunger and needle surfaces Iwhich would destroy the precision ofdelivery volume `and air seepage is prevented by .the gasket assuringmaximum accuracy.

In the above described arrangement the plunger issmall and requires -thesupport of the guide 5).

VThe alternative arrangement of FIG. 6 has a plunger of `greaterdiameter and rigidity than that first described. 'In this FIG. 6arrangement the zerostop sleeve 40 is secured in the body 28 as. in thefirst described arrangement. The longitudinally extend-ing bore 40a ofthe stop sleeve 40 is adapted to op-erably receive the plunger 64, theinner end of the zero stop sleeve 40 having an inwardly tapered recess40a which provides a guide for the free end of the plunger when `thedevice is being assembled. With `this .arrangement the free end of 'theplunger, when `said plunger is inserted into the bore 32 of the body 28'from the rear thereof, will enter the recess 46a and be guided into thebore 40a of said zero stop sleeve 4l). Upon further inward movement ofthe plunger vsaid plunger will pass through the bore of the sleeve 40,through the seal 70, `and into the bore of the needle 12, thuscompleting the assembly. Thereafter the hub 16 is tightened to compressthe `seal about the plunger. In operation the forward end of `the volumeindicating plunger guide 52 cooperates wi-th the scale 36 to indicatethe plunger displacement and said forwardend bottoms on the inner end 46of the zero stop-sleeve 40.

Inthis arrangement Ithe plunger and needle should also beof dissimilarmetals, or .at leasttheir contacting surfaces should be of dissimilarmetals. Very effective results have ybeen obtained with tungsten tostainless steel contacting surfaces for respective parts or a platinumruthenium alloy to stainless steel for the respective contactingsurfaces. v

The invention and its attendant advantages will be understood `from theforegoingdescription land it will be apparent that various changes maybe made in the form, iconstruction and arrangement of the parts of theinvention Without departing from the spirit and scope thereof orsacrificing its material advantages, the embodiment hereinbeforedescribed being merely for purposes of illustration.

I claim: i f l. A syringe of very small volumetric capacity, comprising:

(A) a needle and volumetric barrel reservoir assembly icomprising (a) aneedle of relatively hard met-al, said needle having a sharp point atits free end and having a bore therethrough, (b) and a female needle4hub attached at one end to the end of the needle lopposite the point,said i hub having a bore extending inwardly from the free end, kan outerend portion of said bore being threaded, the inner or forward end ofsaid bore comprising a gasket chamber; (B) a volume indicating devicecomprising,

(a) a transparent body having a bore therethrough, (aa) said body havinga graduated scale there` on with a zero mark adjacent the forward endbut spaced therefrom, p (bb) and an annular ange on the opposite end ofsaid body, `(b) a tubular zero stop and needle screw sleeve securedwithin the forward end .portion of the bore through said 1body with theinner end in register` with the zero mark of the scale, the opposite endof said sleeve extending outwardly r of the `forwardend or said body,(c) a male needle screw secured to the forwardly Y extending portion ofsaidzero stop and needle screw sleeve, said needle screw having anexternally threaded forward end portion for threadable reception in theneedle hub, (d) an inner plunger guide having its forward end secured insaid zero stop and needle screw sleeve and extending rearwardly in thebore of said 1 body, said inner plunger `guide having a boretherethrough and being of smaller external diameter than the internaldiameter of the bore of the body; v t t (C) aplunger assembly including(a) `a plunger of vhard metal, di'lerent from the material of theneedle, and having an external diameter precisely littin-g within thebore through the needle, i j

(b) a tubular volume indicating plunger guide slidably disposed on theinner plunger guide and slida'ble in the bore of the body,

(c) a plunger retaining button secured to the rear end of said plunger,`said plunger extending through the inner plunger guide land needle,

(d) :an externally threaded, tubular plunger retaining screw secured tothe rear end of the volume indicating plunger guide,

(e) a thumb button having a tapped recess in the -forward end thereofthreadably disposed on the plunger retaining screw, said plungerretaining button being `disposed in said recess `and held by the thumbbutton against the adjacent end of the plunger retaining screw tothereby secure together the parts of the plunger assembly,

(f) the parts of the plunger assembly being so proportioned and arrangedthat `when said assembly is moved forwardly in the volume indicatingdevice and needle the forward end of the plunger bottoms at the needlepoint when the forward end of the volume indicating plunger guide abuts`against the rear end of the zero stop and needle screw sleeve, thethumb lbutton and plunger retaining screw being spaced rearwardly of`the flanged end of the body;

(D) and crushed sealing gasket means in the gasket of the threadedneedle hub. 2. A syringe of very small volumetric capacity, comprising:

(A) a needle and Avolumetric barrel reservoir assembly comprising p (q.)a needle of relatively hard material, said needle having a boretherethrough and having a sharp point at its i'rree end,

(b) and a needle hubattached at one end to the end of the needle`opposite the point, said hub having a tapped bore extending inwardlyfrom the free end;

(B) a volume indicating device comprising,

(an) a transparent Abody having a bore therethrough, p

j (mz) said body having a ,graduated scale thereon with a Zero markadjacent the forward end but spaced therefrom, (bb) andan outwardlyextending llange on j the `opposite end of said body,

(b) a tubular zeno `stop sleeve secured within the forward end portionof the ibore through said body with the inner end in register with thezero mark of the Scale, the opposite end of said sleeve extending`outwardly of the forward end of said body,

(c) an externally threaded needle screw secured to the Iforwardlyextending portion of said zero stop sleeve, said needle screw beingthreadably received in the needle hub,

` (d) an inner plunger guide having its forward end secured in said zenostop sleeve and extending rearwardly in the bore of said body, saidinner plunger guide having a bore therethrough and `beingkof smallerexternal-diameter than the internal :diameter of the bore of the body;(C) a plunger assembly including,

(a) a plunger of hard material different from the material of the needleand precisely tting Within the bore through thevneedle,

(b) a `tubular 'volume indicating plunger lguide slidably `disposed :onthe inner plunger guide and slidable in the bore tof the body,

(c) a plunger retaining button lon the rear end of said plunger, saidplunger extending through the inner plunger lguide and the needle,

p (d) an externally threaded plunger retaining screw on the rear end yofthe volume indicating plunger guide,

(e) and a thumb button having a tapped recess in the dorward endthere-of threadabljy disposed on the plunger retainingscrew, saidplunger retaining button being disposed in said recess and held by thethumbl button against the adjacent end of the plunger retaining screw,thereby securing together the plunger and volume indicating plungerguide,

(f) the parts of the plunger assembly being so proportioned and arrangedAthat when said assembly is moved forwardly in the volume int dicatingdevice and needle the forward end 'of the plunger bott-oms at the needlepoint when the Vforward end lof the volume, indicating plunger guideabuts against the rear end of the zero stop `sleeve, the thumb buttonand button and plunger retaining screw being spaced reart tappedl boreextending inwardly from the rear end; (B) a volume indicating devicecomprising,

(a) V a transparent body having a bore therethrough,

(aa) said body having a graduated scale thereon with-a Zero markadjacent the forward end,

(bb) and an outwardly extending flange on thefopposite end of said(body,

(b) a tubular `zero stop Sleeve secured within the dorward end portion`of the bore through said body with the inner end inl register with thezero mark of the scale, the opposite end of said sleeve extendingoutwardly lof the forward end of said body,

(c) a tubular, externally threaded needle screw secured to ftheforwardly extending portion of said zero stop screw sleeve, threadablyreceiving the needle hub thereon,

(d) an inner plunger guide having its ilorward end secured in said zerostop sleeve and extending rearwardly in the bore of said body, saidinner plunger `guide having a bore therethrough and being of smallerexternal diameter than the internal diameter of the bore of the body;

(C) a plunger assembly including,

() a plunger of hard material, different from the material of theneedle, said plunger being precisely iitted within the needle, l

(b) a tubular rvolume indicating plunger guide slidably disposed Ion theinner plunger guide and slidable in the bore of the body,

(c) means for securing together the rear ends of said plunger and volumeindicating plunger guide, said means including a thurnb button,

" (d) the parts of the plunger assembly being so proportioned andarranged that when the plunger is moved forwardly' in the volumeindicating device and needle the lforward end of the plunger bottoms atfthe needle point when the forward end of the volume indicating plungerguide albuts against the rear end of the zeno stop sleeve.

4. In'a syringez (A) a needle and volumetric barrel reservoir assembly,

comprising: A Y

-Y (a)V la tt'ibulary needle having a sharp point at its free end, y

(b) and a tapped 'hub at the end lof the needle opposite the point,

(B) a vol-ume indicating device comprising,

(a) ya transparent tubular body having (au) a graduated scale Ithereonwith a zero mark adjacent the doi-ward end,

(b) a zero stop sleeve secured -withinlthe forward end portion of thebore through lsaid body with the inner end in register with the zeromark of the sca-le, the opposite end of said sleeve exp tending'outwardly of the lforward end of said body,

(c) la tubular, externally threaded needle screw secured to theyforwardly extending portion of said zero stop yand needle screw sleeve,

(d) lan yinner plunger guide Iin said body with its forward -end securedin said Zero stop sleeve, said inner plunger lguide having a `boretheretbroughand being of smaller extern-al `diameter than the interior`oi" 'the body;

' (C) a plunger assembly including,

l(a) aplunger precisely fitting within the needle, (b) a tubular volumeindicating plunger guide slidably disposed on the inner plunger guide,

(c). r`and lmeans operably securingf together the i volume indicatingplunger guide and said plunger, (d) the` parts of the plunger assemblybeing so pnoportioned and arranged that when the plunger is movedforwardly in the volume indiv cat-ing device and needle the forward endof the plunger bottoms at -the needle point when the lforward end lofthe volume indicating plunger `guide abnts `against the rear end of thezero stop sleeve. 5. In a measuring and discharge syringe of very smallvolumetric capacity:

(A) a needle and volumetric 'barrel reservoir assembly comprising:

(a) a tubular needle having a sharp point at its free end;

(B) la plunger precisely iitted `in said needle and slidable therein;

(C) guide and support means for said plunger and said needle;

(D) and Volume indicating means incorporated in the `syringe forindicating the volume displacement in said needle by said plunger.

6. `In a syringe:

(A) atubular needle;

(B) a plunger operably tted and needle;

(C) support means for said plunger;

(D) interconnecting means yconnecting said support means and needle andhaving a chamber therein for gasket and material, said plunger extendingthrough said chamber;

(E) and crushable gasket material in said chamber and in engagement withthe portion of said plunger in said chamber, said interconnecting meanshaving parts movable relative to each other to compress said gasketmaterial on said plunger to provide a seal for said plunger.

7. In a syringe:

(A) a needle and volumetric barrel reservoir assembly, comprising: Y

(a) :a tubular needle having a sharp point at its free end;

(B) a Volume indicating device comprising:

(a) a transparent body having a longitudinal bore therethrough, Y

(aa) a graduated scale thereon with a zero mark adjacent the yforwardend,

(b) a zero stop sleeve secured within the forward end portion of thebore through said body with the inner end in register with the zero markof the scale, the opposite end of said sleeve extending outwardly of theforward end of said body, said sleeve having an inwardly tapering recessin the inner end from which a longitudinal bore extends to the outerend, the ,endV of said needle opposite 'the -sharp pointed end beingSecured to said stop sleeve;

(C) a plunger assembly including (a) a tubular volume indicating plungerguide slidably disposed in the bore of said body,

(b) a plunger preciselyrtting within the needle, and having a rearwardportion disposed in said plunger guide,

(c) and means operably securing together the volume indicating plungerguide and said plunger,

(d) the parts of the plunger assembly being so .proportioned andVarranged that when the plungeris moved forwardly in the volumeindicating `device and needle the forward end of the plunger bottoms atthe needle point when the forward end of the volume indicating slidablein said 9 plunger guide labuts against the rear end of the 2,666,435zero stop sleeve. 2,933,087

References Cite in the le of this patent UNITED STATES PATENTS 5 211g?637,405 Papendell Nov. 21, 1899 157,455 827,693 Korb July 31, 19061,029,528 2,572,155 Hoy-t Oct. 23, 1951 561,5;98 2,590,895 ScarpellinoApr. 1, 1952 365,912

l@ Junkman et al Ian. 19, 1954 Hamilton Apr. 19, 1960 FOREIGN PATENTSGreat Britain July 2, 1898 Sweden June 12, 1953 Germany May 8, 1958`Canada Oct. 31, 1955 Germany Dec. 23, 1922

5. IN A MEASURING AND DISCHARGE SYRINGE OF VERY SMALL VOLUMETRICCAPACITY: (A) A NEEDLE AND VOLUMETRIC BARREL RESERVOIR ASSEMBLYCOMPRISING: (A) A TUBULAR NEEDLE HAVING A SHARP POINT AT ITS FREE END;(B) A PLUNGER PRECISELY FITTED IN SAID NEEDLE AND SLIDABLE THEREIN; (C)GUIDE AND SUPPORT MEANS FOR SAID PLUNGER AND SAID NEEDLE; (D) AND VOLUMEINDICATING MEANS INCORPORATED IN THE SYRINGE FOR INDICATING THE VOLUMEDISPLACEMENT IN SAID NEEDLE BY SAID PLUNGER.